Single-particle dynamics of the Anderson model: a local moment approach

TL;DR

This paper introduces a non-perturbative local moment approach for the Anderson impurity model that effectively captures all energy scales, including Kondo physics and mixed valence regimes, with potential applications to lattice models.

Contribution

A new physically transparent local moment approach that unifies treatment of all energy regimes in the Anderson model, including strong coupling and perturbative limits.

Findings

Successfully captures Kondo universal scaling

Describes mixed valence and empty orbital regimes

Applicable to lattice models via dynamical mean-field theory

Abstract

A non-perturbative local moment approach to single-particle dynamics of the general asymmetric Anderson impurity model is developed. The approach encompasses all energy scales and interaction strengths. It captures thereby strong coupling Kondo behaviour, including the resultant universal scaling behaviour of the single-particle spectrum; as well as the mixed valent and essentially perturbative empty orbital regimes. The underlying approach is physically transparent and innately simple, and as such is capable of practical extension to lattice-based models within the framework of dynamical mean-field theory.